Data collected in the European Cystic Fibrosis Society Patient Registry (ECFSPR) database were used to investigate whether risk factors for death in childhood and adolescents CF patients have different impact in countries of different income. In this way, it is possible to recognize where interventions could improve the quality of care and survival in these patients. We matched deceased and alive patients by age, country, year of follow-up. Multivariable logistic models were developed. In the years of this study, the ECFSPR collected information on 24,416 patients younger than 18 years: 7830 patients were from countries with low/middle income and 16,586 from countries with high income; among these the dead are 102 and 107 (p < 0.001), respectively. The use of oxygen, forced expiratory volume in one second (FEV₁) below 40% and BMI standard deviation score (SDS) below −2 represent risk factors for death. However, some patients from countries with high income remain alive even if their values of FEV₁% and BMI-SDS were low, and some deceased patients from countries with high income had high values of FEV₁% (>60%). Evaluation of mortality in pediatric age may reflect the availability of resources for CF diagnosis and treatment in some countries.

A clinical heterogeneity was reported in patients with Cystic Fibrosis (CF) with the same CFTR genotype and between siblings with CF. We investigated all clinical aspects in a cohort of 101 pairs of siblings with CF (including 6 triplets) followed since diagnosis. Severe lung disease had a 22.2% concordance in sib-pairs, occurred early and the FEV1% at 12 years was predictive of the severity of lung disease in the adulthood. Similarly, CF liver disease occurred early (median: 15 years) and showed a concordance of 27.8% in sib-pairs suggesting a scarce contribution of genetic factors; in fact, only 2/15 patients with liver disease in discordant sib-pairs had a deficiency of alpha-1-antitrypsin (a known modifier gene of CF liver phenotype). CF related diabetes was found in 22 pairs (in 6 in both the siblings). It occurred later (median: 32.5 years) and is strongly associated with liver disease. Colonization by P. aeruginosa and nasal polyposis that required surgery had a concordance > 50% in sib-pairs and were poorly correlated to other clinical parameters. The pancreatic status was highly concordant in pairs of siblings (i.e., 95.1%) but a different pancreatic status was observed in patients with the same CFTR mutations. This suggests a close relationship of the pancreatic status with the “whole” CFTR genotype, including mutations in regulatory regions that may modulate the levels of CFTR expression. Finally, a severe course of CF was evident in a number of patients with pancreatic sufficiency. Physicians involved in care of patients with CF and in genetic counseling must be aware of the clinical heterogeneity of CF even in sib-pairs that, at the state of the art, is difficult to explain.